1. Field of the Invention
This invention relates generally to woodworking equipment, and in particular to an apparatus for precisely orienting and maintaining a workpiece in a predetermined position relative to a cutting tool.
2. Description of Related Art
Operations associated with the cutting, drilling, and shaping of wood or other materials with power tools require the workpiece to be positioned accurately relative to the tool in order to achieve the desired results. In certain applications, the positioning of the workpiece is accomplished through the use of a xe2x80x9cfencexe2x80x9d which is positioned relative to the tool. In some applications, a table saw, for example, the fence may be aligned along the cutting axis of the tool to achieve a substantially straight cut as the workpiece is guided through the saw blade when one edge of the workpiece is maintained in abutting relationship with the fence. In other applications, a miter saw or drill press, for example, the fence may be used, by maintaining one edge of the workpiece in abutting relationship with the fence, to assist in holding the workpiece in a fixed position while the tool passes through the workpiece.
Another positioning device used in connection with a fence is a mechanical stop. Typically, the stop is slidably or removably mounted on the fence with a portion extending down the face of the fence to a point at or near the base of the fence. While the fence is used to position the workpiece in one dimension relative to the tool, the stop allows the workpiece to also be positioned relative to the tool in a dimension along the axis of the fence. When used with a miter head on a table saw, for example, the stop permits positioning of the workpiece such that the workpiece may be cut to a particular length. When used with a router table and fence, for example, the stop may be positioned to stop the workpiece at a predefined position such that the router cut is made only a predefined amount along the axial dimension of the workpiece.
One shortcoming of existing mechanical positioning devices is that they have typically not been capable of providing the accuracy required for many applications. The positioning devices are often large and made of heavy steel to increase accuracy by reducing the amount of mechanical flex in the positioning devices themselves. Their size and weight make these devices cumbersome and difficult to use. Further, despite their size and weight, these devices are still not sufficiently accurate for precision applications.
A shortcoming associated with mechanical stops is that they are typically designed to interface with a particular fence and cannot be used with fences for other tools, or if the fence configuration is modified. For example, in many woodworking operations, it is desirable to connect an auxiliary fence to the face of the existing fence. Most mechanical stops cannot be used together with an auxiliary fence. Some fence manufacturers have attempted to overcome that shortcoming by configuring the fence to permit positioning of the mechanical stop in different locations perpendicular to the face of the fence depending on whether an auxiliary fence is installed. These stop/fence combinations still have the inherent shortfall that the mechanical stop is designed only to interface with a particular fence.
A number of positioning jigs have recently been designed in order to improve the positioning process. For instance, U.S. Pat. No. 4,793,604 granted to Christopher L. Taylor (hereinafter referred to as xe2x80x9cthe Taylor ""604 patentxe2x80x9d) discloses a universal precision positioning jig adapted for precision positioning of a workpiece with respect to a woodworking tool, such as a table saw, router table, drill press, or other tool. The Taylor ""604 patent includes a fixed lower body member and a moveable upper body member, each having mounted thereon a series of tooth-like projections formed into elongated racks. The upper body member is provided with a mount for a fence and is moveable with respect to the fixed lower body member. The racks are meshed together by the tightening of a knob threaded through the middle of the upper and lower body members. The knob is tightened after the fence has been properly positioned to prohibit movement of the upper and lower body members relative to each other during the cutting operation. This, in turn, fixes the position of the fence.
The toothed rack meshing system was further improved upon in U.S. Pat. No. 5,195,730 (hereinafter referred to as xe2x80x9cthe Taylor ""730 patentxe2x80x9d), also granted to Christopher L. Taylor. The Taylor ""730 patent discloses a fixed based and a carriage, the carriage being moveable with respect to the base. Toothed racks such as those taught in the Taylor ""604 patent are also used. One toothed rack is mounted on the carriage and a complementary toothed rack is mounted on the base. The carriage rides in slots on the base and is spring loaded to prevent meshing of the toothed racks until positioning is completed. A cammed clamping lever attached to a rod running through the carriage and base clamps the carriage and the base together, thereby locking and intermeshing the toothed racks to set the carriage position.
One improvement in the art resulting from the Taylor ""604 and ""730 patents is the use of calibrated templates slidably mounted in slots on the carriage. A cursor above the. templates measures the position of the carriage with respect to the cutting blade. Formulas are printed on the templates in order to produce complicated cuts such as dovetail joints or box joints. Using these templates, woodworkers can quickly create intricate wood products previously attainable only by experienced professionals.
The intermeshing teeth on the toothed racks of the Taylor ""604 and ""730 patents are set at intervals of {fraction (1/32)} of an inch, and provide fully repeatable positioning with a precision of {fraction (1/32)} of an inch. The accuracy and rapidity of positioning with the Taylor designs constitutes a substantial improvement in the art. U.S. Pat. No. 5,716,045, which also issued to Christopher L. Taylor (the xe2x80x9cTaylor ""045 patentxe2x80x9d), further improved upon the previous Taylor patents by combining a micropositioning feature with the toothed racks.
Some mechanical stops include pivotal features that allow a portion of the mechanical stop providing support for the workpiece to pivot between a work position and a standby position. In the work position, the stop is configured to engage and position the workpiece along the fence relative to the cutting tool. The stop can be rotated into the standby position such that it no longer engages the workpiece.
U.S. Pat. No. 5,337,641 issued to Duginske discloses a stop and fence combination for woodworking applications. The stop is slidably positionable along the length of the fence using a bolt/nut combination with the nuts located within a T-slot along the top of the fence. The stop is configured such that it may be rotated up and away from the fence so that the fence may be used without the stop while the stop remains connected to the fence.
U.S. Pat. No. 5,768,966, which also issued to Duginske, discloses a fence geometry that permits the rotatable stop from the ""641 patent to be used when an auxiliary fence is attached to the face of the main fence. The ""966 patent accommodates the auxiliary fence by adding a second T-slot adjacent to and parallel to the T-slot of the ""641 patent. When the stop is used without an auxiliary fence, the stop is connected to the fence using the T-slot further from the fence face. When the stop is used with an auxiliary fence, the stop is connected to the fence using the T-slot nearer the fence face.
One shortcoming associated with rotatable stops is the mechanical flex associated with pivotable parts. This flex, under some circumstances, can reduce the positioning accuracy of the stop. Another shortcoming is evident when using a pivotable stop in conjunction with a mitered workpiece. A mitered workpiece having a xe2x80x9csharpxe2x80x9d corner can act as a wedge and actually slide between the pivotable stop and the fence, causing the stop to rotate upward toward the standby position. This rotation of the pivotable stop decreases and in some cases eliminates the ability of the stop to hold the workpiece.
Traditional stops (i.e. non-rotatable stops) can also experience inaccuracy problems when positioning mitered workpieces. A sharp corner of the workpiece can wedge itself between the stop and the fence. This can produce several undesirable effects, including improper cuts to the workpiece, damage to the mitered comer of the workpiece, and potential danger to the woodworker.
Accordingly, there remains a need in the woodworking industry for an improved positioning jig having the properties of precision, repeatability, and interchangeability that are required by modem-day woodworkers. It would therefore be beneficial to the woodworking industry to provide a mechanical stop system embodying an efficient and accurate design having a rotatable mechanical stop. Moreover, it would be beneficial to provide a mechanical stop system that could be used with either a single fence or an auxiliary fence installed on a basic fence. It would also be a great improvement in the art if the mechanical stop itself could be made to interface with the positioning fences used for different tools so that when a mechanical stop is required for different applications, the stop alone, as opposed to the stop and fence combination, may be installed for use with a particular tool. Further, it is desirable to provide a mechanical stop that prevents movement of the workpiece between the stop and the fence.
All references cited herein are incorporated by reference to the maximum extent allowable by law. To the extent a reference may not be fully incorporated herein, it is incorporated by reference for background purposes and indicative of the knowledge of one of ordinary skill in the art.
The present invention seeks to resolve the above and other problems with the prior art. More particularly, the invention advances the art by providing an expandable mechanical stop system achieving the objects listed below.
It is an object of the present invention to provide a mechanical stop that is configured to be used in combination with a workpiece positioning fence on a variety of tools.
It is further an object of the present invention to provide such a mechanical stop that is expandable so that it can be used in combination with a workpiece positioning fence both when an auxiliary fence is installed and when no such auxiliary fence is installed, or with work piece positioning fences of differing thicknesses.
It is further an object of the present invention to provide a mechanical stop system having a track that is used as a fence when attached to a woodworking or other tool.
It is further an object of the present invention to provide a mechanical stop system that is capable of accurate, finite incremental positioning.
It is further an object of the present invention to provide a mechanical stop system that incorporates a micro-positioning capability to provide even greater accuracy and resolution in positioning.
It is further an object of the present invention to provide a mechanical stop system that prevents the workpiece from translating laterally along the fence (or track) such that a portion of the workpiece would move between the stop and the fence.
To achieve the foregoing objects, and in accordance with the invention as embodied and described herein, the present invention includes a mechanical stop that is configured for attachment to a track. The track includes a vertical face for abutting a workpiece during woodworking and other operations. The mechanical stop includes a positioning body that is configured to be releasably attached to the track. A stop arm is pivotally connected to the positioning body and provides further support and positioning capability for the workpiece when the stop arm is in a work position. When the stop arm is rotated into a standby position, the stop arm can no longer engage the workpiece. The stop arm includes a rear face that is substantially adjacent to the vertical face of the track when the stop arm is disposed in the work position. Finally, the mechanical stop includes anti-biasing means which prevent the workpiece from dislodging the stop arm from the work position during operation.
In another embodiment of the present invention, a woodworking machinery jig and fixture system is provided that includes an L-shaped track having a base adjustably mounted to the track. The track includes a first leg and a second leg, the first leg having a front side and the second leg having a top side. The top side of the second leg includes a guide in which the base is adjustably mounted. A flip stop is pivotally mounted to the base and is capable of rotation between a work position and a standby position. The flip stop includes a rear face that is substantially adjacent to the front side of the first leg when the flip stop is in the work position. Anti-biasing means are provided to prevent a workpiece from dislodging the flip stop from the work position during operation.
In still another embodiment of the present invention, a mechanical stop is provide for positioning a workpiece during woodworking or other operations. The mechanical stop works in conjunction with a track having a vertical face that abuts the workpiece. The mechanical stop includes a positioning that is configured to be releasably attached to the track. The positioning body can be incrementally adjusted along a longitudinal axis of the track using incremental adjustment means. A stop arm is connected to the positioning body and provides additional support and positioning capability for the workpiece. The stop arm includes a rear face that is substantially adjacent to the vertical face of the track when the positioning body is installed on the track. Anti-biasing means are provided to prevent the workpiece from dislodging the stop arm such that the workpieced could slide between the rear face and the vertical face.
Other objects, features, and advantages of the present invention will become apparent with reference to the drawings and detailed description which follow.